This application claims the priority of German application 197 27 685.7, filed in Germany on Jun. 20, 1997, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an air guiding device.
From German Patent Document DE 44 41 592 A1, an air guiding device is known in the case of which an upper wing is arranged between lateral cheeks and a spoiler is arranged at a distance thereto. The side cheeks bound an air gap formed between the wing and the spoiler.
It is an object of the invention to provide an air guiding device which improves road grip of the vehicle due to a negative lift force generated by the air flow resulting in optimal vehicle handling, particularly at high speeds.
This and other objects haven been achieved according to the present invention by providing an air guiding device for improving a road grip of a vehicle, comprising: an upper wing and a lower wing supported on the vehicle extending approximately in a transverse direction of the vehicle, said upper and lower wings being arranged at a distance from each other and being connected at transverse ends with each other via respective end cheeks, said end cheeks having an approximately U-shaped cross-section, said upper and lower wings and said end cheeks defining a gap through which air flows.
The principal advantages achieved by the invention are that, in addition to an improved road grip, optimized aerodynamics are achieved; that is, that the air guiding device still reduces the drag coefficient and the air flow can flow around and through the device without any significant disadvantageous air swirl formations.
For this purpose, the wings of the air guiding device are connected by way of end cheeks defining a beak-shaped opening toward the rear, so that the air can flow through the wings on the exterior side over obliquely disposed surfaces, as well as over interior-side air guiding surfaces on the cheeks without any significant drag.
So that the air flow, coming from the roof over the rear end of the vehicle, can enter between the wings without significant swirls, the leading edge of the upper wing is rounded toward the rear, with respect to the driving direction.
For achieving a negative lift on the exterior surface, the upper wing element has an inwardly directed (i.e., concave) curvature in the longitudinal direction, the interior surface having an outwardly directed (i.e., convex) larger curvature which points to an approximately plane interior wing surface of the lower wing element.
The cross-section of the flow-through opening between the two wing elements has an approximately trapezoidal shape and is designed such that the air flow can be guided from the roof and an area of the lateral surfaces without interruption through the air gap. In the case of the design of the wing elements as well as of the air gap and of the end cheeks, it is important that a compromise is achieved between an optimally operating negative lift and an acceptable drag force.
So that a fast mounting and demounting of the air guiding device can be carried out on the vehicle, it is fixedly connected with the rear lid prior to mounting on the vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.